Work flow to mesh a geometry

After I obtained geometry, for example in the explanation in this post, the next step is to prepare a case dictionary for OpenFOAM. It tells what kind of physics you want to play with. And there are a lot of things you can play with.

In this post, a general step will be posted. Further improvements will be made along the way as I do more simulations.

Step 0 Check mesh

Orintate the mesh towards x-positive direction
Export from blender warning: the first line needs to be changed: solid final_rotate

Step 1 BlockMesh

Look for 8 points to build a block
Obtain coordinates: (a b c)

Extend block An example would be:

-x: time 5
x: time 10
y: time 5
-y: time 5
z: time 5
-y: time 5

A good example looks like this:

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(-60  50 45)
( 90  50 45)
( 90 -50 45)
(-60 -50 45)
(-60  50 -45)
( 90  50 -45)
( 90 -50 -45)
(-60 -50 -45)

(-300  250 225)
( 900  250 225)
( 900 -250 225)
(-300 -250 225)
(-300  250 -225)
( 900  250 -225)
( 900 -250 -225)
(-300 -250 -225)

Replace vertices in blockMeshDict file
Move stl file to /constant/triSurface

Step 2 Run commands

blockmesh
snappyHexMesh -overwrite Without overwrite, you can visualize the refinement process.

Step 3 Fine tune `snappyHexMesh`

Refine some regions. This part will be further expanded in the future posts.

Step 4 Run simulation

For example, simpleFoam.

FAQ

Error: `Cannot find triSurfaceMesh at xxx`

Make sure the mesh file is in format of ASC-II, instead of binary. Double check the first line of that stl file.

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